Light of wavelength `lambda_(1)` enters a medium with refractive index `n_(2)` from a medium with refractive index `n_(1)`. What is the wavelength of light in second medium ?

Explanation

Wavelength of first medium = `lambda_(1)`.
Refractive index of first medium = `n_(1)`
Let the wavelength of second medium = `lambda_(2)`
Refractive index of second medium = `n_(2)`
Light enters from first medium to second medium `implies (n_(2))/(n_(1)) = (c_(1))/(c_(2)) = (lambda_(1))/(lambda_(2))` (`therefore` v=const)
`implies lambda_(2) = (lambda_(1)n_(1))/(n_(2))`